Recipient immunization with an irradiated tumor cell vaccine increases GVT activity and prevents death from tumor.
One month after C3H.SW→C57BL/6 BMT, recipients (205-immune, n = 12) were immunized with 50 Gy-irradiated 205IL-2/TK cells. Control recipients (nonimmune, n = 8) were not immunized. Ten days after the first vaccine, micrometastases were established in all recipients by intravenous injection of 1 × 105 205 tumor cells, and 205-immune recipients received 3 more vaccines at weekly intervals. Lung nodules were counted after death or after day 100 for each recipient; pulmonary nodule counts were not available for 1 mouse in the nonimmune group because the carcass was severely cannibalized before autopsy. 205-immune recipients had significantly enhanced survival (A, P < .0001) and a significant reduction of lung nodules (B, P = .0011) compared to nonimmune recipients. Results were pooled from 2 independent experiments.
